1. Field of the Invention
The present invention relates to a finger-operable pump adapted for installation on a non-pressurized, hand-held container of a liquid consumer product to form a liquid dispensing package. More particularly, this invention relates to an assembly incorporated in the liquid dispensing pump for automatically sealing it against leakage.
Liquid dispensing pumps are now commonly used to dispense various liquid products from hand-held, non-pressurized containers. For example, these pumps can be used to dispense liquids such as window and all purpose cleaners, insecticides, germicides, room deodorizers and the like as well as personal products such as hair sprays, deodorants, and colognes. In addition, these pumps serve not only as dispensers but also as closures for containers during shipment, handling, and storage.
2. Description of the Prior Art
Finger-operable liquid dispensing pumps for dispensing liquid consumer products are well known. Typically, these pumps include a housing which defines a pumping chamber. A piston or plunger is mounted for reciprocal pumping movement in the chamber and has a discharge passage therethrough which conducts liquid from the chamber. Conventional check valves control liquid movement during pumping operation by preventing return flow of liquid through the pump. The plunger may also be equipped with an actuator button having a atomizing device to break the liquid dispensed through it into fine particles to form a mist.
Since these dispensing pumps also frequently serve as closures for the containers on which they are installed, both when used and not used, they should provide assured sealing capability to prevent leakage from the container. Particularly, they should prevent leakage during shipping and related handling as well as during consumer use when the package may be inverted or accidentally upset or dropped.
Various pump designs have been proposed which include leakage preventing features. For example, copending U.S. Pat. application Ser. No. 559,894, now U.S. Pat. No. 3,949,906 (Peterson et al.), assigned to the assignee of the present invention, discloses a sealing assembly having two seal members which are shifted between seated and unseated positions by rotation of one of relative to the other. Since one seal member is non-rotatably coupled to the housing and the other to the plunger, relative rotation is effected by rotating the pump plunger relative to the pump housing. A camming action is thus produced which either unseats the seal members or permits them to reengage.
Another seal arrangement, disclosed in U.S. Pat. No. 3,239,151 (Boris), comprises a housing defining a pump chamber in which a plunger having a stem is telescopically received. A tube having a valve member at its lower end is slidably mounted in the plunger stem and is coupled at its upper end to an actuator button. When the button is depressed, the tube is also depressed relative to the plunger to unseat the valve member and provide a discharge passage from pump. A sliding seal is made between the tube and plunger stem or, in another embodiment, between the tube and the pump housing. In different embodiments, the valve element makes either a conical or an annular surface seal with an appropriate valve seat.
Other dispenser pumps similar to that shown in the Boris Patent are disclosed in U.S. Pat. Nos. 3,362,344 (Duda); 3,583,605 (Corsette); 3,627,206 (Boris); 3,640,470 (Susuki et al.); 3,680,790 (Boris); and 3,724,726 (Susuki et al.).